A. Field of Invention
This invention pertains to the art of methods and apparatuses for snowplows and more specifically to a hydraulic system that can move two snowplow wings at substantially the same time and substantially the same speed regardless of the disparity of loads on the wings.
B. Description of the Related Art
It is well known in the art to provide snowplow assemblies for use in moving snow from roads, driveways, parking lots and other such surfaces. Typically, the snowplow assembly is attached to a vehicle, such as a pickup truck. Usually, the snowplow assembly can be moved by the driver/operator of the vehicle. Thus, for example, the operator can adjust a controller from inside the occupant compartment of the vehicle to raise, lower and pivot the snowplow assembly.
In recent years, the snowplow industry has provided additional snowplow assembly designs and movement options. A relatively new snowplow assembly, for example, is termed a V-plow. A V-plow is essentially two snowplow blades combined onto a single frame. In this case, each snowplow blade is generally considered a wing and typically, each wing can be controlled independently of the other wing. Another known type of snowplow assembly includes a snowplow blade that has a non-pivotal middle portion and two wings. Each pivotal wing is placed on one end of the snowplow's middle portion. As with the V-plow, it is common that each pivotal wing can be controlled independent of the opposite wing.
It is known to move a snowplow assembly using a hydraulic system. As a result, hydraulic components such as hydraulic cylinders, hydraulic piping and hoses, appropriate fittings and the like are required to operate the snowplow assembly. The hydraulic system also generally includes a control mechanism. Typically, the operator manipulates a handle, switches, or buttons on the controller that causes the controller to transmit a corresponding signal to the control mechanism. The control mechanism receives the signal from the controller and then controls the components of the hydraulic system so that the flow of hydraulic fluid is directed appropriately to cause the proper movement of the snowplow assembly. Such control mechanisms are known to include a base plate, a hydraulic reservoir or tank, a hydraulic pump unit, and the necessary control valves such as solenoid valves and/or cartridge valves.
Although known snowplow assemblies having at least two wings work well for their intended purpose, they have several disadvantages. Often, the load acting on one wing of a snowplow assembly may be substantially different from the load acting on the other wing. Referring now to FIG. 1, this disparity in loads acting on each wing may occur, for one non-limiting example, when the operator is plowing snow to the side of the road (with the first wing 34 in a position relatively perpendicular to the road's longitudinal axis and the second wing 36 pivoted in direction D toward the vehicle) and desires to adjust the wings into what is known as scoop mode. Scoop mode is the condition where both wings are pivoted fully forward. More specifically, scoop mode is accomplished when the first wing 34 is pivoted fully in direction A and the second wing 36 is pivoted fully in direction C. Typically, the load (created by the amount of snow or ice in front of the wings) is not the same for both wings. As a result, with all known snowplow assemblies such an adjustment into scoop mode means that the wing with the lesser load will move first and the wing with the greater load will move only after a delay. More specifically, with all known snowplow assemblies adjustment into scoop mode means that the first hydraulic cylinder pivoting the lesser loaded wing will begin moving quickly but the second hydraulic cylinder pivoting the greater loaded wing will only begin moving when the hydraulic pressure in the hydraulic piping to the first cylinder equals the hydraulic pressure in the hydraulic piping to the second cylinder. Such delayed and uneven movement of the wings is undesirable as it waists time and may cause some snow to be left behind (not plowed).
The present invention minimizes this difficulty by providing a flow divider that enables two or more snowplow wings to move at substantially the same time and substantially the same speed regardless of the disparity of loads acting on the wings.